Increasing persistence in undergraduate science majors: a model for institutional support of underrepresented students.

The 6-yr degree-completion rate of undergraduate science, technology, engineering, and mathematics (STEM) majors at U.S. colleges and universities is less than 40%. Persistence among women and underrepresented minorities (URMs), including African-American, Latino/a, Native American, and Pacific Islander students, is even more troubling, as these students leave STEM majors at significantly higher rates than their non-URM peers. This study utilizes a matched comparison group design to examine the academic achievement and persistence of students enrolled in the Program for Excellence in Education and Research in the Sciences (PEERS), an academic support program at the University of California, Los Angeles, for first- and second-year science majors from underrepresented backgrounds. Results indicate that PEERS students, on average, earned higher grades in most "gatekeeper" chemistry and math courses, had a higher cumulative grade point average, completed more science courses, and persisted in a science major at significantly higher rates than the comparison group. With its holistic approach focused on academics, counseling, creating a supportive community, and exposure to research, the PEERS program serves as an excellent model for universities interested in and committed to improving persistence of underrepresented science majors and closing the achievement gap

A genetic assessment of parentage in the blackspot sergeant damselfish, Abudefduf sordidus (Pisces: Pomacentridae)

Microsatellite markers were used to investigate the reproductive behavior of the damselfish Abudefduf sordidus at Johnston Atoll, Central Pacific Ocean. Genetic results indicated that ten males maintained guardianship over their nest territories for up to nine nest cycles during a 3.5 month period. Genotypes of 1025 offspring sampled from 68 nests (composed of 129 clutches) were consistent with 95% of the offspring being sired by the guardian male. Offspring lacking paternal alleles at two or more loci were found in 19 clutches, indicating that reproductive parasitism and subsequent alloparental care occurred. Reconstructed maternal genotypes allowed the identification of a minimum of 74 different females that spawned with these ten territorial males. Males were polygynous, mating with multiple females within and between cycles. Genetic data from nests, which consisted of up to four clutches during a reproductive cycle, indicated that each clutch usually had only one maternal contributor and that different clutches each had different dams. Females displayed sequential polyandry spawning with one male within a cycle but switched males in subsequent spawning cycles. These results highlight new findings regarding male parasitic spawning, polygyny, and sequential polyandry in a marine fish with exclusive male paternal care.Published versio

Designing a graphical user interface for a bilateral negotiation support system

Graphical User Interfaces (GUI) are quickly becoming the standard operating environment for most software programs and operating systems. Ease of use, rapid learning and the ability to retain complex task sequences and operations are some of the advantages attributed to this type of interface. When properly implemented the GUI can provide a natural interaction between the user and the computer. Initial acceptance and continued use of any program can be greatly enhanced by proper design of this interface. It is expected that this trend toward visual representation of a task's objects and actions will be more fully developed and expanded in future years. This thesis explored the principles of interface design with particular attention given to the specific characteristics associated with GUI design. Unique design concepts associated with Negotiation Support Systems were also considered. These design techniques and principles were then applied in the analysis and design of the graphical user interface for a Bilateral Negotiation Support System based on multiple attribute utility theory. The program was written in Microsoft Visual Basic for use under the Microsoft Windows 3.0 operating environment.http://archive.org/details/designinggraphic1094538555Lieutenant Commander, United States Naval ReserveApproved for public release; distribution is unlimited

Comparative Phylogeography in Fijian Coral Reef Fishes: A Multi-Taxa Approach towards Marine Reserve Design

Delineating barriers to connectivity is important in marine reserve design as they describe the strength and number of connections among a reserve’s constituent parts, and ultimately help characterize the resilience of the system to perturbations at each node. Here we demonstrate the utility of multi-taxa phylogeography in the design of a system of marine protected areas within Fiji. Gathering mtDNA control region data from five species of coral reef fish in five genera and two families, we find a range of population structure patterns, from those experiencing little (Chrysiptera talboti, Halichoeres hortulanus, and Pomacentrus maafu), to moderate (Amphiprion barberi, Wst = 0.14 and Amblyglyphidodon orbicularis Wst = 0.05) barriers to dispersal. Furthermore estimates of gene flow over ecological time scales suggest speciesspecific, asymmetric migration among the regions within Fiji. The diversity among species-specific results underscores the limitations of generalizing from single-taxon studies, including the inability to differentiate between a species-specific result and a replication of concordant phylogeographic patterns, and suggests that greater taxonomic coverage results in greater resolution of community dynamics within Fiji. Our results indicate that the Fijian reefs should not be managed as a single unit, and that closely related species can express dramatically different levels of population connectivity

Seeking Gauge Bileptons in Linear Colliders

A promising direction to find physics beyond the standard model is to look for violation of $L_{e,\mu,\tau}$ conservation. In particular the process $e^- e^- \to \mu^- \mu^-$ with the exchange of a gauge bilepton has a striking signal without background and is predicted in the most economical model to have a cross-section an order of magnitude higher than previous estimates.Comment: 4 pages LaTeX and 5 postscript figure

Genomic signatures of host-associated divergence and adaptation in a coral-eating snail, Coralliophila violacea (Kiener, 1836).

The fluid nature of the ocean, combined with planktonic dispersal of marine larvae, lowers physical barriers to gene flow. However, divergence can still occur despite gene flow if strong selection acts on populations occupying different ecological niches. Here, we examined the population genomics of an ectoparasitic snail, Coralliophila violacea (Kiener 1836), that specializes on Porites corals in the Indo-Pacific. Previous genetic analyses revealed two sympatric lineages associated with different coral hosts. In this study, we examined the mechanisms promoting and maintaining the snails' adaptation to their coral hosts. Genome-wide single nucleotide polymorphism (SNP) data from type II restriction site-associated DNA (2b-RAD) sequencing revealed two differentiated clusters of C. violacea that were largely concordant with coral host, consistent with previous genetic results. However, the presence of some admixed genotypes indicates gene flow from one lineage to the other. Combined, these results suggest that differentiation between host-associated lineages of C. violacea is occurring in the face of ongoing gene flow, requiring strong selection. Indeed, 2.7% of all SNP loci were outlier loci (73/2,718), indicative of divergence with gene flow, driven by adaptation of each C. violacea lineage to their specific coral hosts

Episymbiotic microbes as food and defence for marine isopods : unique symbioses in a hostile environment

Author Posting. © Royal Society, 2005. This article is posted here by permission of Royal Society for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society of London B 272 (2005): 1209-1216, doi:10.1098/rspb.2005.3082.Symbioses profoundly affect the diversity of life, often through novel biochemical services that symbionts provide to their hosts. These biochemical services are typically nutritional enhancements and less commonly defensive, but rarely both simultaneously. On the coral reefs of Papua New Guinea, we discovered unique associations between marine isopod crustaceans (Santia spp.) and episymbiotic microbes. Transmission electron microscopy and pigment analyses show that episymbiont biomass is dominated by large (20–30μm) cyanobacterial cells. The isopods consume these photosymbionts and ‘cultivate’ them by inhabiting exposed sunlit substrates, a behaviour made possible by symbionts' production of a chemical defence that is repulsive to fishes. Molecular phylogenetic analyses demonstrated that the symbiotic microbial communities are diverse and probably dominated in terms of population size by bacteria and small unicellular Synechococcus-type cyanobacteria. Although largely unknown in the oceans, defensive symbioses probably promote marine biodiversity by allowing niche expansions into otherwise hostile environments.This work was supported by an NSF Predoctoral Fellowship awarded to J.B.W and a grant from the North Carolina Biotechnology Center to N.L and Richard Manderville (Wake Forest University)

High Gene Flow Due to Pelagic Larval Dispersal Among South Pacific Archipelagos in Two Amphidromous Gastropods (Neritomorpha: Neritidae)

The freshwater stream fauna of tropical oceanic islands is dominated by amphidromous species, whose larvae are transported to the ocean and develop in the plankton before recruiting back to freshwater habitat as juveniles. Because stream habitat is relatively scarce and unstable on oceanic islands, this life history would seem to favor either the retention of larvae to their natal streams, or the ability to delay metamorphosis until new habitat is encountered. To distinguish between these hypotheses, we used population genetic methods to estimate larval dispersal among five South Pacific archipelagos in two amphidromous species of Neritid gastropod (Neritina canalis and Neripteron dilatatus). Sequence data from mitochondrial COI revealed that neither species is genetically structured throughout the Western Pacific, suggesting that their larvae have a pelagic larval duration of at least eight weeks, longer than many marine species. Additionally, the two species have recently colonized isolated Central Pacific archipelagos in three independent events. Since colonization, there has been little to no gene flow between the Western and Central Pacific archipelagos in Neritina canalis, and high levels of gene flow across the same region in Neripteron dilatatus. Both species show departures from neutrality and recent dates for colonization of the Central Pacific archipelagos consistent with frequent extinction and recolonization of stream populations in this area. Similar results from other amphidromous species suggest that unstable freshwater habitats promote long-distance dispersal capabilities

Phylogeography of the crown-of-thorns starfish in the Indian Ocean

Background: Understanding the limits and population dynamics of closely related sibling species in the marine realm is particularly relevant in organisms that require management. The crown-of-thorns starfish Acanthaster planci, recently shown to be a species complex of at least four closely related species, is a coral predator infamous for its outbreaks that have devastated reefs throughout much of its Indo-Pacific distribution. Methodology/Principal Findings: In this first Indian Ocean-wide genetic study of a marine organism we investigated the genetic structure and inferred the paleohistory of the two Indian Ocean sister-species of Acanthaster planci using mitochondrial DNA sequence analyses. We suggest that the first of two main diversification events led to the formation of a Southern and Northern Indian Ocean sister-species in the late Pliocene-early Pleistocene. The second led to the formation of two internal clades within each species around the onset of the last interglacial. The subsequent demographic history of the two lineages strongly differed, the Southern Indian Ocean sister-species showing a signature of recent population expansion and hardly any regional structure, whereas the Northern Indian Ocean sister-species apparently maintained a constant size with highly differentiated regional groupings that were asymmetrically connected by gene flow. Conclusions/Significance: Past and present surface circulation patterns in conjunction with ocean primary productivity were identified as the processes most likely to have shaped the genetic structure between and within the two Indian Ocean lineages. This knowledge will help to understand the biological or ecological differences of the two sibling species and therefore aid in developing strategies to manage population outbreaks of this coral predator in the Indian Ocean